attach(hellung)
summary(hellung)
hellung

par(mfrow = c(1, 2))

plot(conc, diameter, pch = glucose)  #两组数据的散点图
plot(conc, diameter, pch = glucose, log = "xy")  #双对数图

tethym_gluc <- hellung[glucose == 1, ]  #培养液加葡萄糖
tethym_nogluc <- hellung[glucose == 2, ]  #培养液不加葡萄糖
lm_gluc <- lm(log10(diameter) ~ log10(conc), data = tethym_gluc)
lm_nogluc <- lm(log10(diameter) ~ log10(conc), data = tethym_nogluc)

abline(lm.nogluc)  #回归直线
abline(lm.gluc)  #回归直线

lm_tethym <- lm(log10(diameter) ~ log10(conc) * glucose)
summary(lm_tethym)
anova(lm_tethym)
